It has been over one century since fat transplantation/fat grafting was proposed in literature by German doctor, Neüber in 1893 [1]. Fat transplantation/fat grafting has been considered for a long time as a procedure for soft tissue augmentation or filling and thus has been often applied to aspects of reconstructive surgery and cosmetic surgery [2.3].
In general, the side effects of fat transplantation/fat grafting can be one or a combination of absorption, infection, embolism, cyst formation, calcification, ossification, pseudotumor, necrosis, asymmetry, skin necrosis/fistula formation, iatrogenic nerve/vascular injuries, carvenous sinus thrombosis and so forth [4]. After investigation into the causes of said side effects, most are directly related to improper, uneven or excess placement of fat during the fat transplantation/fat grafting procedure. As a result, the correct positioning of fat in a proper, even and precise manner becomes the most critical concern during the clinical application of fat transplantation/fat grafting.
According to the article “Structural Fat Grafting: More Than a Permanent Filler”, composed by celebrated plastic surgeon S R Coleman in the well-known journal, Plast. Reconstr. Surg. in 2006, several valuable points [5] pertinent to the correct placement of fat were disclosed. The important points are summarized as follows;
While transplanting fat, the accuracy of the placed volume is extremely important; once the fat is injected into human body, the fat mass can hardly be manipulated again.
When an infiltration cannula is withdrawn each time and the fat is injected spontaneously into the human body during facial fat transplantation, the transplanted fat volume must be precisely controlled down to 1/10 cc per injection.
The maximum fat injection volume into a specific area of the body, e.g. the eyelid, should be approximately 1/30 cc or even as low as 1/50 cc.
However, while performing fat transplantation using the 1-cc syringe suggested by S R Coleman during clinical application, a precise advancement of 1/10 cc of fat per-injection is a very difficult task and, not to mention that an injection volume with an accuracy of 1/30 or 1/50 cc is actually beyond human control. For the sake of better surgical effects, the Byron Medical Co. has marketed the DISPOS-A-JECT™ SYSTEM as illustrated in FIG. 1. However, such a system secures a minimum output volume of 1/10 cc only and obviously fails to achieve the smaller volume demands of 1/30 or 1/50 cc. Besides, the 1-cc syringe connected with the DISPOS-A-JECT™ SYSTEM requires a more costly 1-cc BD luer-lock syringe instead of a regular 1-cc syringe supplied in most hospitals and clinics, thus resulting in the deficiency of both operational convenience and universality.
While using the DISPOS-A-JECT™ SYSTEM to perform fat transplantation surgery, as shown in FIG. 1, the plunger 81 of syringe 8 is removed first; then an adapter 82 of the SYSTEM is inserted into syringe 8 to thereby advance the fat. During the operation, the fat is exposed to air and there are concerns that the fat cells may be contaminated and have a low survival rate. Moreover, as the included angle between the gun surface of the SYSTEM and the injection needle 83 and the injection needle aperture 84 is fixed, surgeons do not have flexibility in adjusting the injection angle while the SYSTEM is being clinically applied to fat grafting surgery. As a result, injection surface deviation or injection difficulty easily takes place in the case of a rough operation.
Taking into account the aforementioned descriptions, accuracy of surgery, airtight property of the equipment, simple operation and so on, a novel fat transplantation device is indeed required to resolve these drawbacks arising from the conventional technique.
Notes:
    [1] Neüber. Fetttransplantation. Zentrabl. Chir. 22:66, 1893    [2] Chajchir, A., and Benzaquen, I. Fat-grafting injection for soft-tissue augmentation. Plast. Reconstr. Surg. 84:921-24, 1989.    [3] Chajchir, A., Benzaquen, I., Wexler, E., et al. Fat injection. 14:127-36, 1990.    [4] Khawaja, H. A., Handez-perez, E. Fat transfer review: controversies, complications, their prevention, and treatment. Int. J. Cosmet. Surg. Aesth. Dermatol. 4:131-38, 2002.    [5] Coleman, S. R. Structural fat grafting: more than a permanent filler. Plast. Reconstr, Surg. 118:108s-20s, 2006.